The number of women with ERV infection has increased rapidly during the past seven years. Despite this, comparatively little is known about the natural history of the disease in women. The rate of decline of immunologic function and predictors of disease progression, such as oral thrush and hairy leukoplakia, have not been determined for women. More information is needed on the gynecological conditions that appear to be influenced by HIV infection. There is also little understanding of the barriers that may prevent HIV-infected and high-risk women from receiving health care and participating in clinical research. We propose to create a regional cohort of 450-600 HIV-infected and 90-120 high-risk, uninfected women as part of the WIHS cooperative multi-site prospective epidemiologic study. The sample size will depend on WIHS goals and funding. The study cohort will be based in the Bay Area Research Consortium on Women and AIDS (BARCWA): a collaboration of university- and community-based investigators. BARCWA is co-sponsored by the Departments of Medicine, Stomatology, and Obstetrics and Gynecology at the University of California, San Francisco. The consortium arrangement provides the study with a study sample which is diverse in terms of socioeconomic status, HIV risk-factors and ethnicity. The consortium includes investigators with widely varied scientific and clinical backgrounds which brings to the research enormous expertise in cohort management, clinical data collection, laboratory assessment and community outreach. The aims of the three components of this application are: 1) Describe the natural history of HIV infection and related conditions in women; 2) Create a comprehensive model of access to health care and clinical trials in women who are known to have HIV infection or to be at high risk for it; 3) Evaluate the prevalence, incidence and prognostic significance of oral lesions in women; and 4) Describe the means by which this proposed study site would participate in the central WIHS activities.